Phenoxazine derivatives for organic electroluminescent devices

ABSTRACT

The present invention relates to the compounds of the formulae (1) and (2) and to organic electroluminescent devices, in particular blue-emitting devices, in which these compounds are used as host material or dopant in the emitting layer and/or as hole-transport material and/or as electron-transport material.

RELATED APPLICATIONS

This application is a national stage entry, filed pursuant to 35 U.S.C.§ 371, of PCT/EP2016/001242, filed Jul. 15, 2016, which claims thebenefit of European Patent Application No. 15181177.5, filed Aug. 14,2015, which is incorporated herein by reference in its entirety.

The present invention relates to a compound of the formula (1) or (2),to the use of the compound in an electronic device, and to an electronicdevice comprising a compound of the formula (1) or (2). The presentinvention furthermore relates to a process for the preparation of acompound of the formula (1) or (2) and to a formulation comprising oneor more compounds of the formula (1) or (2).

The development of functional compounds for use in electronic devices iscurrently the subject of intensive research. The aim here is, inparticular, the development of compounds with which improved propertiesof electronic devices in one or more relevant points can be achieved,such as, for example, power efficiency, lifetime or colour coordinatesof the emitted light.

In accordance with the present invention, the term electronic device istaken to mean, inter alia, organic integrated circuits (OICs), organicfield-effect transistors (OFETs), organic thin-film transistors (OTFTs),organic light-emitting transistors (OLETs), organic solar cells (OSCs),organic optical detectors, organic photoreceptors, organic field-quenchdevices (OFQDs), organic light-emitting electrochemical cells (OLECs),organic laser diodes (O-lasers) and organic electroluminescent devices(OLEDs).

Of particular interest is the provision of compounds for use in thelast-mentioned electronic devices called OLEDs. The general structureand the functional principle of OLEDs are known to the person skilled inthe art and are described, inter alia, in U.S. Pat. No. 4,539,507, U.S.Pat. No. 5,151,629, EP 0676461 and WO 1998/27136.

Further improvements are still necessary with respect to the performancedata of OLEDs, in particular with a view to broad commercial use, forexample in display devices or as light sources. Of particular importancein this connection are the lifetime, the efficiency and the operatingvoltage of the OLEDs and the colour values achieved. In particular inthe case of blue-emitting OLEDs, there is potential for improvement withrespect to the lifetime of the devices. In addition, it is desirable,for use as functional materials in electronic devices, for the compoundsto have high thermal stability and a high glass-transition temperatureand to be capable of sublimation without decomposition.

An important starting point for achieving the said improvements is thechoice of the emitter compound employed in the electronic device.

Blue-fluorescent emitters known from the prior art are a multiplicity ofcompounds, in particular arylamines containing one or more condensedaryl groups and/or indenofluorene groups. Examples thereof are thepyrene-arylamines disclosed in U.S. Pat. No. 5,153,073 and thepyrene-arylamines disclosed in WO 2012/048780. Further examples ofarylamine emitters are benzoindenofluorenamines, for example inaccordance with WO 2008/006449 or WO 2008/003464, anddibenzoindenofluorenamines, for example in accordance with WO2007/140847.

Furthermore, the use of fluorenamines which contain aromatic groupscondensed onto the fluorene system is known in the prior art. Thecompounds which contain two or more arylamino groups are employed asfluorescent emitters (US 2012/0161615). However, the compounds exhibitgreen to green-blue emission and not blue emission.

Furthermore, KR 2009/131536 and WO 2004/061048 disclose benzo-fluorenederivatives which carry a diphenylamino group. However, compounds ofthis type have excessively short-wave emission to be used asblue-fluorescent emitters, or their efficiency and lifetime areunsatisfactory on use in OLEDs.

The use of phenoxazine derivatives as emitting compounds in OLEDs isalso known from the prior art (WO 2012/150001, US 2007/0176541, KR2013/0115855).

However, further improvements are still necessary with respect to thecolour values achieved in the case of blue-emitting OLEDs. Moreparticularly, there is a need for deep-blue fluorescent emitters forOLEDs, which exhibit very good colour properties in terms of color-depthand narrow emission band and at the same time still exhibit goodproperties in terms of lifetime, efficiency and operating voltage of theOLEDs.

Furthermore, there is also a need for alternative hole-transportmaterials. In hole-transport materials in accordance with the prior art,the voltage generally increases with the layer thickness of thehole-transport layer. In practice, a greater layer thickness of thehole-transport layer would frequently be desirable, but this often hasthe consequence of a higher operating voltage and worse performancedata. In this connection, there is a need for novel hole-transportmaterials which have high charge-carrier mobility, enabling thickerhole-transport layers to be achieved with an only slight increase in theoperating voltage.

The prior art discloses the use, in particular, of arylamine compoundsand carbazole compounds as hole-transport materials for OLEDs.

The applications WO 2010/083871, WO 2011/107186 and WO 2012/150001disclose the use of heterocyclic derivatives of anthracenes which aresubstituted by one or more arylamino groups or by one or more carbazolegroups as functional materials in OLEDs, preferably as hole-transportand hole-injection materials.

Again furthermore, the application US 2010/0019658 discloses the use ofdihydroacridine derivatives which carry aryl or heteroaryl groups assubstituents of the methylene group of the dihydroacridine as functionalmaterials in OLEDs.

However, there continues to be a need for alternative hole-transport andhole-injection materials for use in OLEDs. In particular, there is aneed for materials with which the above-mentioned, highly desiredimprovements in the performance data and properties of OLEDs can beachieved.

There is likewise a need for alternative matrix materials for use inOLEDs and in other electronic devices. In particular, there is a needfor matrix materials for phosphorescent dopants and for matrix materialsfor mixed-matrix systems, which preferably result in good efficiency, along lifetime and a low operating voltage of the electronic devices.

The present invention is thus based on the technical object of providingcompounds which are suitable for use in electronic devices, such as, forexample, OLEDs, and which can be employed, in particular, as blueemitters, as hole-transport materials and/or as matrix materials.

Surprisingly, it has been found that compounds in which an aromatic (orheteroaromatic) ring system or diarylamino group is linked para to theoxygen atom of a phenoxazine compound are very suitable for use inorganic electroluminescent devices. These compounds exhibit very goodcolour properties in terms of color-depth and narrow emission band andat the same time still exhibit good properties in terms of lifetime,efficiency and operating voltage of the OLEDs. Furthermore, thesecompounds are very suitable as hole-transport and hole-injectionmaterials and as matrix materials for phosphorescent emitters. Anincrease in the efficiency and lifetime of the organic electronic devicecompared with materials in accordance with the prior art is possibleusing these materials. Furthermore, these materials are very suitablefor use in organic electronic devices since they have a high glasstransition temperature. The present invention therefore relates to thesematerials and to the use thereof in organic electronic devices.

As part of the present invention, it has now been found that compoundsof the formula (1) or (2) indicated below are highly suitable for theabove-mentioned uses.

The invention thus relates to a compound of formula (1) or (2)

-   -   where the following applies to the symbols and indices:    -   Ar is an aromatic or heteroaromatic ring system having 5 to 30        aromatic ring atoms, which may be substituted by one or more        radicals R²;    -   Ar¹ is, on each occurrence, identically or differently, a group        of one of the following formula (Ar1-1) to (Ar1-4)

-   -   in which the dashed bond indicate the linking to the group        Ar^(S) or to the phenoxazine structure if Ar^(S) is absent;    -   V is, on each occurrence, identically or differently, equal to        CR², N or two adjacent groups V stand for a group of the formula        (V-1) or (V-2);

-   -   -   in which the dashed bonds indicate the linking of this unit;

    -   Ar² is, on each occurrence, identically or differently, an aryl        group having 10 to 18 aromatic ring atoms, which may be        substituted by one or more radicals R²;

    -   Ar^(S) is on each occurrence, identically or differently, an        aromatic or heteroaromatic ring system having 5 to 40 aromatic        ring atoms, which may in each case also be substituted by one or        more radicals R²;

    -   E¹, E², E³ are on each occurrence, identically or differently,        selected from B(R¹), C(R¹)₂, Si(R¹)₂, C═O, C═NR¹, C═C(R¹)₂, O,        S, S═O, SO₂, N(R¹), P(R¹) and P(═O)R¹;        -   or E¹, E² and/or E³ represents a group of the following            formula (E-1),

-   -   -   where the dashed bonds indicate the bonding to the            5-membered ring comprising E¹, E² or E³;

    -   R, R¹, R², R³ are on each occurrence, identically or        differently, H, D, F, Br, Cl, I, C(═O)R⁴, CN, Si(R⁴)₃, N(R⁴)₂,        P(═O)(R⁴)₂, S(═O)R⁴, S(═O)₂R⁴, a straight-chain alkyl or alkoxy        group having 1 to 20 C atoms or a branched or cyclic alkyl or        alkoxy group having 3 to 20 C atoms or an alkenyl or alkynyl        group having 2 to 20 C atoms, where the above-mentioned groups        may each be substituted by one or more radicals R⁴ and where one        or more CH₂ groups in the above-mentioned groups may be replaced        by —R⁴C═CR⁴—, —C≡C—, Si(R⁴)₂, C═O, C═NR⁴, —C(═O)O—, —C(═O)NR⁴—,        NR⁴, P(═O)(R⁴), —O—, —S—, SO or SO₂, or an aromatic or        heteroaromatic ring system having 5 to 30 aromatic ring atoms,        which may in each case be substituted by one or more radicals        R⁴, or an aryloxy or heteroaryloxy group having 5 to 30 aromatic        ring atoms, which may be substituted by one or more radicals R⁴,        where two adjacent substituents R, two adjacent substituents R¹,        two adjacent substituents R² and/or two adjacent substituents R³        may be linked to one another and may form an aliphatic or        aromatic ring;

    -   R⁴ is on each occurrence, identically or differently, H, D, F,        Br, Cl, I, C(═O)R⁵, CN, Si(R⁵)₃, N(R⁵)₂, P(═O)(R⁵)₂, S(═O)R⁵,        S(═O)₂R⁵, a straight-chain alkyl or alkoxy group having 1 to 20        C atoms or a branched or cyclic alkyl or alkoxy group having 3        to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C        atoms, where the above-mentioned groups may each be substituted        by one or more radicals R⁵ and where one or more CH₂ groups in        the above-mentioned groups may be replaced by —R⁵C═CR⁵—, —C≡C—,        Si(R⁵)₂, C═O, C═NR⁵, —C(═O)O—, —C(═O)NR⁵—, NR⁵, P(═O)(R⁵), —O—,        —S—, SO or SO₂, or an aromatic or heteroaromatic ring system        having 5 to 30 aromatic ring atoms, which may in each case be        substituted by one or more radicals R⁵, or an aryloxy or        heteroaryloxy group having 5 to 30 aromatic ring atoms, which        may be substituted by one or more radicals R⁵, where two        adjacent substituents R⁴ may be linked to one another and may        form an aliphatic or aromatic ring;

    -   R⁵ is on each occurrence, identically or differently, H or an        aliphatic, aromatic and/or heteroaromatic hydrocarbon radical        having 1 to 20 C atoms, in which, in addition, H atoms may be        replaced by F; two adjacent substituents R⁵ here may also form a        mono- or polycyclic aliphatic or aromatic ring system with one        another;

    -   a, b, c, d are, identically or differently selected from 0 or 1;        where a=0, b=0, c=0 or d=0 means that the corresponding bridge        is not present;

    -   where        a+b=1 or 2; and        c+d=1 or 2;

    -   f is, identically or differently, on each occurrence 0, 1, 2 or        3;

    -   g, h are, identically or differently, on each occurrence 0, 1 or        2; where g+a+b≤3 and h+c+d≤3;

    -   m is, identically or differently, on each occurrence 0, 1, 2, 3        or 4;

    -   i is, identically or differently, on each occurrence 0, 1, 2 or        3, where i=0 means that the group Ar^(S) is absent and replaced        by a single bond.

An aryl group in the sense of this invention contains 6 to 60 aromaticring atoms; a heteroaryl group in the sense of this invention contains 5to 60 aromatic ring atoms, at least one of which is a heteroatom. Theheteroatoms are preferably selected from N, O and S. This represents thebasic definition. If other preferences are indicated in the descriptionof the present invention, for example with respect to the number ofaromatic ring atoms or the heteroatoms present, these apply.

An aryl group or heteroaryl group here is taken to mean either a simplearomatic ring, i.e. benzene, or a simple heteroaromatic ring, forexample pyridine, pyrimidine or thiophene, or a condensed (annellated)aromatic or heteroaromatic polycycle, for example naphthalene,phenanthrene, quinoline or carbazole. A condensed (annellated) aromaticor heteroaromatic polycycle in the sense of the present applicationconsists of two or more simple aromatic or heteroaromatic ringscondensed with one another.

An aryl or heteroaryl group, which may in each case be substituted bythe above-mentioned radicals and which may be linked to the aromatic orheteroaromatic ring system via any desired positions, is taken to mean,in particular, groups derived from benzene, naphthalene, anthracene,phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene,benzanthracene, benzophenanthrene, tetracene, pentacene, benzopyrene,furan, benzofuran, isobenzofuran, dibenzofuran, thiophene,benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole,isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine,phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline,benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole,imidazole, benzimidazole, naphthimidazole, phenanthrimidazole,pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole,benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole,1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine,pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine,naphthyridine, azacarbazole, benzocarboline, phenanthroline,1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole,1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole,1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine,1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine,1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine andbenzothiadiazole.

An aryloxy group in accordance with the definition of the presentinvention is taken to mean an aryl group, as defined above, which isbonded via an oxygen atom. An analogous definition applies toheteroaryloxy groups.

An aromatic ring system in the sense of this invention contains 6 to 60C atoms in the ring system. A heteroaromatic ring system in the sense ofthis invention contains 5 to 60 aromatic ring atoms, at least one ofwhich is a heteroatom. The heteroatoms are preferably selected from N, Oand/or S. An aromatic or heteroaromatic ring system in the sense of thisinvention is intended to be taken to mean a system which does notnecessarily contain only aryl or heteroaryl groups, but instead inwhich, in addition, a plurality of aryl or heteroaryl groups may beconnected by a non-aromatic unit (preferably less than 10% of the atomsother than H), such as, for example, an sp³-hybridised C, Si, N or Oatom, an sp²-hybridised C or N atom or an sp-hybridised C atom. Thus,for example, systems such as 9,9′-spirobifluorene, 9,9′-diarylfluorene,triarylamine, diaryl ether, stilbene, etc., are also intended to betaken to be aromatic ring systems in the sense of this invention, as aresystems in which two or more aryl groups are connected, for example, bya linear or cyclic alkyl, alkenyl or alkynyl group or by a silyl group.Furthermore, systems in which two or more aryl or heteroaryl groups arelinked to one another via single bonds are also taken to be aromatic orheteroaromatic ring systems in the sense of this invention, such as, forexample, systems such as biphenyl, terphenyl or diphenyltriazine.

An aromatic or heteroaromatic ring system having 5-60 aromatic ringatoms, which may in each case also be substituted by radicals as definedabove and which may be linked to the aromatic or heteroaromatic groupvia any desired positions, is taken to mean, in particular, groupsderived from benzene, naphthalene, anthracene, benzanthracene,phenanthrene, benzophenanthrene, pyrene, chrysene, perylene,fluoranthene, naphtha-cene, pentacene, benzopyrene, biphenyl,biphenylene, terphenyl, ter-phenylene, quaterphenyl, fluorene,spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene,cis- or trans-indenofluorene, truxene, isotruxene, spirotruxene,spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran,thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole,indole, isoindole, carbazole, indolocarbazole, indenocarbazole,pyridine, quinoline, isoquinoline, acridine, phenanthridine,benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline,phenothiazine, phenoxazine, pyrazole, indazole, imidazole,benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole,pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole,naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole,1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine,benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene,2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene,4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine,phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline,phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole,1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole,1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole,1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine,tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine,purine, pteridine, indolizine and benzothiadiazole, or combinations ofthese groups.

For the purposes of the present invention, a straight-chain alkyl grouphaving 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, inwhich, in addition, individual H atoms or CH₂ groups may be substitutedby the groups mentioned above under the definition of the radicals, ispreferably taken to mean the radicals methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl,cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl,cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl,pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl,pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, hep-tenyl,cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl,pen-tynyl, hexynyl or octynyl. An alkoxy orthioalkyl group having 1 to40 C atoms is preferably taken to mean methoxy, trifluoromethoxy,ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy,n-pentoxy, s-pentoxy, 2-methylbutoxy, n-hexoxy, cyclohexyloxy,n-heptoxy, cycloheptyl-oxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy,pentafluoroethoxy, 2,2,2-tri-fluoroethoxy, methylthio, ethylthio,n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio,t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio,n-heptylthio, cycloheptylthio, n-octylthio, cyclooctylthio,2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio,2,2,2-trifluoro-ethylthio, ethenylthio, propenylthio, butenylthio,pentenylthio, cyclopenten-ylthio, hexenylthio, cyclohexenylthio,heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio,ethynylthio, propynylthio, butynylthio, pentyn-ylthio, hexynylthio,heptynylthio or octynylthio.

The formulation that two radicals are adjacent, for the purposes of thepresent application, is taken to mean that:

-   -   two radicals are linked to two C atoms, wherein the two C atoms        are directly linked to each other; or    -   two radicals are linked to the same C atom.

The formulation that two or more radicals may form a ring with oneanother is, for the purposes of the present application, intended to betaken to mean, inter alia, that the two radicals are linked to oneanother by a chemical bond. This is illustrated by the followingschemes:

Furthermore, however, the above-mentioned formulation is also intendedto be taken to mean that, in the case where one of the two radicalsrepresents hydrogen, the second radical is bonded at the position towhich the hydrogen atom was bonded, with formation of a ring. This isillustrated by the following scheme:

In accordance with a preferred embodiment, the following applies to theindices a, b, c and d in formula (2):a+c=1 and b+d=0; orb+d=1 and a+c=0.

In accordance with a preferred embodiment, E⁰ is a single bond and Ar¹is, on each occurrence identically, a group of one of the followingformula (Ar1′-1) to (Ar1′-4)

In accordance with a preferred embodiment, the group Ar is an aromaticor heteroaromatic ring system having 5 to 18 aromatic ring atoms. Morepreferably, Ar is an aromatic ring system having 5 to 18 aromatic ringatoms.

Ar is particularly preferably selected from the group consisting ofphenyl, fluorenyl, spirobifluorenyl, benzofluorenyl, biphenyl,terphenyl, quaterphenyl, naphtyl, anthracyl, phenanthryl, chrysenyl,pyrenyl, each of which may be substituted by one or more radicals R².

Ar is very particularly preferably selected from one of the followingformulae (ArN-1) to (ArN-32)

where the dashed bond indicates the bond to the nitrogen atom of thephenoxazine structure depicted in formula (1) or (2), where R² has thesame meaning as above and where the groups of formulae (ArN-1) to(ArN-32) may be substituted on each free position by one or moreradicals R².

Among the formulae (ArN-1) to (ArN-32), the formulae (ArN-1) to (ArN-22)are preferred.

In accordance with a preferred embodiment, the group Ar¹ stands for agroup of formula (A-1) to (A-4), where E¹ is selected from C(R¹)₂,Si(R¹)₂, O, N or S, or E¹ stands for a group of formula (E-1) as definedabove.

Ar¹ is very particularly preferably selected from one of the followingformulae

where the dashed bond indicates the bond to the groups Ar^(S) or to thephenoxazine structure if Ar^(S) if absent, where R¹ has the same meaningas above and where the groups of formulae (Ar1-1) to (Ar1-24) may besubstituted on each free position by one or more radicals R².

In accordance with a preferred embodiment, the group Ar² is selectedfrom the group consisting of naphtyl, anthracyl, phenanthryl, chrysenyland pyrenyl, preferably naphtyl, each of which may be substituted by oneor more radicals R².

In a preferred embodiment of the invention, the compound of the formula(1) or (2) is selected from the compounds of the following formulae(1-1-a), (2-1-a) and (2-2-a),

-   -   where Ar² is a group of one of the following formulae (Ar2-1) to        (Ar2-3)

-   -   in which the dashed bond indicates the linking to the        phenoxazine structure and the sign * indicates the linking        position to the group E²; and where each free position of the        naphtyl group in formulae (Ar2-1) to (Ar2-3) may be substituted        by a group R²; and    -   where the other symbols Ar, V, R and E¹ and indices i, f, g and        h have the same meaning as described in claim 1; and with the        proviso that in formula (1-1-a), V is C when the linking to the        phenoxazine structure or phenyl phenoxazine structure takes        place via this group V.

In a particularly preferred embodiment of the invention, the compoundsof formulae (1-1-a), (2-1-a) and (2-2-a) are selected from the compoundsof the following formulae (1-1-b) to (2-2-e)

where the symbols and indices have the same meaning as described aboveand where each free position of the two phenyl rings condensed on thecentral oxazine ring in formulae (1-1-b) to (2-2-d) may be substitutedby a group R.

In accordance with a further preferred embodiment, a maximum of threegroups V in an aromatic ring are equal to N, particularly preferably amaximum of two groups V in an aromatic ring are equal to N, and veryparticularly preferably a maximum of one group V in an aromatic ring isequal to N.

It is furthermore preferred for not more than two adjacent groups V in asix-membered ring to be equal to N.

It is especially preferred for V to be equal to CR², when the group V isnot part of a group of the formula (V-1) or (V-2).

It is furthermore preferred for the groups E¹, E² and E³ to be adivalent bridge selected, on each occurrence, identically ordifferently, from the group consisting of C(R¹)₂, Si(R¹)₂, O, N or S, ora group of formula (E-1) as defined above, the groups C(R¹)₂ or thegroup of formula (E-1) are particularly preferred, the group C(R¹)₂ isvery particularly preferred.

In accordance with a preferred embodiment, R, R¹, R² and R³ areselected, identically or differently on each occurrence, from the groupconsisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 Catoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherethe above-mentioned groups may each be substituted by one or moreradicals R⁴ and where one or more CH₂ groups in the above-mentionedgroups may be replaced by —R⁴C═CR⁴—, —C≡C—, C═O, —O—, —S—, an aromaticor heteroaromatic ring system having 5 to 30 aromatic ring atoms, whichmay in each case be substituted by one or more radicals R⁴, where twoadjacent substituents R, two adjacent substituents R¹, two adjacentsubstituents R² and/or two adjacent substituents R³, may be linked toone another and may form an aliphatic or aromatic ring.

It is particularly preferred that R is selected, identically ordifferently on each occurrence, from the group consisting of H, D, F, astraight-chain alkyl group having 1 to 10 C atoms or a branched orcyclic alkyl group having 3 to 10 C atoms, where the above-mentionedgroups may each be substituted by one or more radicals R⁴.

It is particularly preferred that R¹ is selected, identically ordifferently on each occurrence, from the group consisting of H, D, F, astraight-chain alkyl group having 1 to 10 C atoms or a branched orcyclic alkyl group having 3 to 10 C atoms, where the above-mentionedgroups may each be substituted by one or more radicals R⁴ and where oneor more CH₂ groups in the above-mentioned groups may be replaced by—R⁴C═CR⁴—, —C≡C—, C═O, —O—, —S—, an aryl or heteroaryl group having 5 to14 aromatic ring atoms, which may in each case be substituted by one ormore radicals R⁴, where two adjacent substituents R¹, may be linked toone another and may form an aliphatic or aromatic ring.

It is particularly preferred that R² is selected, identically ordifferently on each occurrence, from the group consisting of H, D, F, astraight-chain alkyl group having 1 to 10 C atoms or a branched orcyclic alkyl group having 3 to 10 C atoms, where the above-mentionedgroups may each be substituted by one or more radicals R⁴ and where oneor more CH₂ groups in the above-mentioned groups may be replaced by—R⁴C═CR⁴—, —C≡C—, C═O, —O—, —S—, an aryl or heteroaryl ring systemhaving 5 to 14 aromatic ring atoms, which may in each case besubstituted by one or more radicals R⁴, where two adjacent substituentsR², may be linked to one another and may form an aliphatic or aromaticring. It is very particularly preferred that R² is H, F, a tert-butyl ora phenyl group.

It is preferred that R⁴ is on each occurrence, identically ordifferently, H, F, a straight-chain alkyl group having 1 to 10 C atomsor a branched or cyclic alkyl or group having 3 to 10 C atoms, where theabove-mentioned groups may each be substituted by one or more radicalsR⁵, or an aryl or heteroaryl group having 5 to 14 aromatic ring atoms,which may in each case be substituted by one or more radicals R⁵.

For compounds which are processed by vacuum evaporation, the alkylgroups preferably have not more than four C atoms, particularlypreferably not more than 1 C atom. For compounds which are processedfrom solution, suitable compounds are also those which are substitutedby linear, branched or cyclic alkyl groups having up to 10 C atoms orwhich are substituted by oligoarylene groups, for example ortho-, meta-,para- or branched terphenyl or quaterphenyl groups.

Examples of suitable compounds according to the invention are thecompounds shown in the following table:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

The synthesis of the compounds according to the invention can be carriedout by processes of preparative organic chemistry which are generallyknown to the person skilled in the art. Examples of reactions which arepreferably employed are halogenations and transition metal-catalysedcoupling reactions, preferably Suzuki couplings and Buchwald couplings.

Illustrative processes for the preparation of the compounds according tothe invention are presented below. The processes shown are particularlysuitable for the preparation of the compounds according to theinvention. However, alternative processes are conceivable and possiblypreferable in certain cases. Accordingly, the person skilled in the artwill be able to mod-ify the processes shown below within the scope ofhis general expert knowledge.

The compounds according to the invention are preferably synthesised asshown in Scheme 1 and Scheme 2 or as shown in Scheme 1 and Scheme 3. Allcompounds shown may optionally be substituted by one or more organicradicals.

The compounds are reacted with an aryl or heteroaryl compound Ar—X in aSuzuki coupling, which introduces the substituent on the phenoxazinebackbone para to the N atom (Scheme 2).

Alternatively, the compounds are reacted with an aryl or heteroarylcompound comprising a carboxylate ester group ROOC—Ar—X in a Suzukicoupling, which introduces the substituent on the phenoxazine backbonepara to the N atom (Scheme 3). The carboxylate substituents are thenalkylated via a reaction using an organometallic and the compound isfinally condensed.

The synthetic process shown above has an illustrative character and maybe modified in a suitable manner by the person skilled in the art in thearea of organic synthesis if this is advantageous for the synthesis ofcertain embodiments of compounds according to the invention.

The present invention thus furthermore relates to a process for thepreparation of compounds of the formula (1) or (2) which ischaracterised in that one or more transition metal-catalysed couplingreactions by means of which aromatic or heteroaromatic ring systems areintroduced as substituents para to the N atom from a phenoxazinederivative. The transition metal-catalysed coupling reactions arepreferably selected from Hartwig-Buchwald couplings and Suzukicouplings.

The compounds according to the invention described above, in particularcompounds which are substituted by reactive leaving groups, such asbromine, iodine, chlorine, boronic acid or boronic acid ester, can beused as monomers for the production of corresponding oligomers,dendrimers or polymers. Suitable reactive leaving groups are, forexample, bromine, iodine, chlorine, boronic acids, boronic acid esters,amines, alkenyl or alkynyl groups having a terminal C—C double bond orC—C triple bond, oxiranes, oxetanes, groups which undergo acycloaddition, for example a 1,3-dipolar cycloaddition, such as, forexample, dienes or azides, carboxylic acid derivatives, alcohols andsilanes.

The invention therefore furthermore relates to oligomers, polymers ordendrimers containing one or more compounds of the formula (1) or (2),where the bond(s) to the polymer, oligomer or dendrimer may be localisedat any desired positions in formula (1) or (2) which are substituted byR or R². Depending on the linking of the compound of the formula (1) or(2), the compound is a constituent of a side chain of the oligomer orpolymer or a constituent of the main chain. An oligomer in the sense ofthis invention is taken to mean a compound which is built up from atleast three monomer units. A polymer in the sense of the invention istaken to mean a compound which is built up from at least ten monomerunits. The polymers, oligomers or dendrimers according to the inventionmay be conjugated, partially conjugated or non-conjugated. The oligomersor polymers according to the invention may be linear, branched ordendritic. In the structures linked in a linear manner, the units of theformula (1) or (2) may be linked directly to one another or they may belinked to one another via a divalent group, for example via asubstituted or unsubstituted alkylene group, via a heteroatom or via adivalent aromatic or heteroaromatic group. In branched and dendriticstructures, for example, three or more units of the formula (1) or (2)may be linked via a trivalent or polyvalent group, for example via atrivalent or polyvalent aromatic or heteroaromatic group, to form abranched or dendritic oligomer or polymer.

The same preferences as described above for compounds of the formula (1)or (2) apply to the recurring units of the formula (1) and (2) inoligomers, dendrimers and polymers.

For the preparation of the oligomers or polymers, the monomers accordingto the invention are homopolymerised or copolymerised with furthermonomers. Suitable and preferred comonomers are selected from fluorenes(for example in accordance with EP 842208 or WO 2000/22026),spirobifluor-enes (for example in accordance with EP 707020, EP 894107or WO 2006/061181), para-phenylenes (for example in accordance with WO1992/18552), carbazoles (for example in accordance with WO 2004/070772or WO 2004/113468), thiophenes (for example in accordance with EP1028136), dihydrophenanthrenes (for example in accordance with WO2005/014689 or WO 2007/006383), cis- and trans-indenofluorenes (forexample in accordance with WO 2004/041901 or WO 2004/113412), ketones(for example in accordance with WO 2005/040302), phenanthrenes (forexample in accordance with WO 2005/104264 or WO 2007/017066) or also aplurality of these units. The polymers, oligomers and dendrimers usuallyalso contain further units, for example emitting (fluorescent orphosphorescent) units, such as, for example, vinyltriarylamines (forexample in accordance with WO 2007/068325) or phosphorescent metalcomplexes (for example in accordance with WO 2006/003000), and/orcharge-transport units, in particular those based on triarylamines.

The polymers and oligomers according to the invention are generallyprepared by polymerisation of one or more types of monomer, at least onemonomer of which results in recurring units of the formula (1) or (2) inthe polymer. Suitable polymerisation reactions are known to the personskilled in the art and are described in the literature. Particularlysuitable and preferred polymerisation reactions which result in C—C orC—N links are the following:

(A) SUZUKI polymerisation;

(B) YAMAMOTO polymerisation;

(C) STILLE polymerisation; and

(D) HARTWIG-BUCHWALD polymerisation.

The way in which the polymerisation can be carried out by these methodsand the way in which the polymers can then be separated off from thereaction medium and purified is known to the person skilled in the artand is described in detail in the literature, for example in WO2003/048225, WO 2004/037887 and WO 2004/037887.

The present invention thus also relates to a process for the preparationof the polymers, oligomers and dendrimers according to the invention,which is characterised in that they are prepared by SUZUKIpolymerisation, YAMAMOTO polymerisation, STILLE polymerisation orHARTWIG-BUCHWALD polymerisation. The dendrimers according to theinvention can be prepared by processes known to the person skilled inthe art or analogously thereto. Suitable processes are described in theliterature, such as, for example, in Frechet, Jean M. J.; Hawker, CraigJ., “Hyperbranched polyphenylene and hyperbranched polyesters: newsoluble, three-dimensional, reactive polymers”, Reactive & FunctionalPolymers (1995), 26(1-3), 127-36; Janssen, H. M.; Meijer, E. W., “Thesynthesis and characterization of dendritic molecules”, MaterialsScience and Technology (1999), 20 (Synthesis of Polymers), 403-458;Tomalia, Donald A., “Dendrimer molecules”, Scientific American (1995),272(5), 62-6; WO 2002/067343 A1 and WO 2005/026144 A1.

For the processing of the compounds according to the invention from theliquid phase, for example by spin coating or by printing processes,formulations of the compounds according to the invention are necessary.These formulations can be, for example, solutions, dispersions oremulsions. It may be preferred to use mixtures of two or more solventsfor this purpose. Suitable and preferred solvents are, for example,toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene,tetralin, veratrol, THF, methyl-THF, THP, chlorobenzene, dioxane,phenoxytoluene, in particular 3-phenoxytoluene, (−)-fenchone,1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene,1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol,2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole,3,5-dimethylanisole, acetophenone, terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene,decalin, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, NMP,p-cymene, phenetol, 1,4-diisopropylbenzene, dibenzyl ether, diethyleneglycol butyl methyl ether, triethylene glycol butyl methyl ether,diethylene glycol dibutyl ether, triethylene glycol dimethyl ether,diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether,tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene,pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene,1,1-bis(3,4-dimethylphenyl)ethane or mixtures of these solvents.

The invention therefore furthermore relates to a formulation, inparticular a solution, dispersion or emulsion, comprising at least onecompound of the formula (1) or (2) or at least one polymer, oligomer ordendrimer containing at least one unit of the formula (1) or (2), and atleast one solvent, preferably an organic solvent. The way in whichsolutions of this type can be prepared is known to the person skilled inthe art and is described, for example, in WO 2002/072714, WO 2003/019694and the literature cited therein.

The compounds of the formula (1) or (2) according to the invention aresuitable for use in electronic devices, in particular in organicelectroluminescent devices (OLEDs). Depending on the substitution, thecompounds are employed in different functions and layers.

The invention therefore furthermore relates to the use of a compound ofthe formula (1) or (2) in an electronic device. The electronic devicehere is preferably selected from the group consisting of organicintegrated circuits (OICs), organic field-effect transistors (OFETs),organic thin-film transistors (OTFTs), organic light-emittingtransistors (OLETs), organic solar cells (OSCs), organic opticaldetectors, organic photoreceptors, organic field-quench devices (OFQDs),organic light-emitting electrochemical cells (OLECs), organic laserdiodes (O-lasers) and particularly preferably organic electroluminescentdevices (OLEDs).

The invention furthermore relates to an electronic device comprising atleast one compound of the formula (1) or (2). The electronic device ispreferably selected from the devices indicated above. Particularpreference is given to an organic electroluminescent device comprisinganode, cathode and at least one emitting layer, characterised in that atleast one organic layer comprises at least one compound of the formula(1) or (2).

Apart from cathode, anode and emitting layer, the organicelectroluminescent device may also comprise further layers. These areselected, for example, from in each case one or more hole-injectionlayers, hole-transport layers, hole-blocking layers, electron-transportlayers, electron-injection layers, electron-blocking layers,exciton-blocking layers, inter-layers, charge-generation layers (IDMC2003, Taiwan; Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K.Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL DeviceHaving Charge Generation Layer) and/or organic or inorganic p/njunctions. However, it should be pointed out that each of these layersdoes not necessarily have to be present and the choice of layers isalways dependent on the compounds used and in particular also on whetherthe electroluminescent device is fluorescent or phosphorescent.

The sequence of the layers of the organic electroluminescent device ispreferably the following:

anode-hole-injection layer-hole-transport layer-emittinglayer-electron-transport layer-electron-injection layer-cathode.

It should again be pointed out here that not all the said layers have tobe present, and/or that further layers may additionally be present.

The organic electroluminescent device according to the invention maycomprise a plurality of emitting layers. These emission layers in thiscase particularly preferably have in total a plurality of emissionmaxima between 380 nm and 750 nm, resulting overall in white emission,i.e. various emitting compounds which are able to fluoresce orphosphoresce and which emit blue or yellow or orange or red light areused in the emitting layers. Particular preference is given tothree-layer systems, i.e. systems having three emitting layers, where atleast one of these layers preferably comprises at least one compound ofthe formula (1) or (2) and where the three layers exhibit blue, greenand orange or red emission (for the basic structure see, for example, WO2005/011013). It should be noted that, for the generation of whitelight, an emitter compound used individually which emits in a broadwavelength range may also be suitable instead of a plurality of emittercompounds emitting in colour.

The compounds according to the invention may alternatively and/oradditionally also be present in the hole-transport layer or in anotherlayer.

It is preferred for the compound of the formula (1) or (2) to beemployed in an emitting layer. In particular, the compound of theformula (1) or (2) is suitable for use as emitting material (emittercompound). The compounds of formula (1) or (2) are very particularlysuitable as emitting material.

The compounds according to the invention are particularly suitable foruse as blue-emitting emitter compound. The electronic device concernedmay comprise a single emitting layer comprising the compound accordingto the invention or it may comprise two or more emitting layers. Thefurther emitting layers here may comprise one or more compoundsaccording to the invention or alternatively other compounds.

If the compounds according to the invention are employed as emittingmaterial in an emitting layer, it is preferably employed in combinationwith one or more matrix materials.

The proportion of the compound according to the invention in the mixtureof the emitting layer is in this case preferably between 0.1 and 50.0%by vol., particularly preferably between 0.5 and 20.0% by vol., veryparticularly preferably between 1.0 and 10.0% by vol. Correspondingly,the proportion of the matrix material or matrix materials is between50.0 and 99.9% by vol., particularly preferably between 80.0 and 99.5%by vol., very particularly preferably between 90.0 and 99.0% by vol.

Preferred matrix materials for use in combination with the materialsaccording to the invention as emitters are selected from the classes ofthe oligoarylenes (for example 2,2′,7,7′-tetraphenylspirobifluorene inaccordance with EP 676461 or dinaphthylanthracene), in particular theoligoarylenes containing condensed aromatic groups, theoligoarylenevinylenes (for example DPVBi or spiro-DPVBi in accordancewith EP 676461), the polypodal metal complexes (for example inaccordance with WO 2004/081017), the hole-conducting compounds (forexample in accordance with WO 2004/058911), the electron-conductingcompounds, in particular ketones, phosphine oxides, sulfoxides, etc.(for example in accordance with WO 2005/084081 and WO 2005/084082), theatropisomers (for example in accordance with WO 2006/048268), theboronic acid derivatives (for example in accordance with WO 2006/117052)or the benz-anthracenes (for example in accordance with WO 2008/145239).Particularly preferred matrix materials are selected from the classes ofthe oligoarylenes, comprising naphthalene, anthracene, benzanthraceneand/or pyrene or atropisomers of these compounds, theoligoarylenevinylenes, the ketones, the phosphine oxides and thesulfoxides. Very particularly preferred matrix materials are selectedfrom the classes of the oligoarylenes, comprising anthracene,benzanthracene, benzophenanthrene and/or pyrene or atropisomers of thesecompounds. An oligoarylene in the sense of this invention is intended tobe taken to mean a compound in which at least three aryl or arylenegroups are bonded to one another.

Preferred matrix materials for use in combination with the compound ofthe formula (1) or (2) in the emitting layer are depicted in thefollowing table.

The compounds according to the invention can also be employed in otherlayers, for example as hole-transport materials in a hole-injection orhole-transport layer or electron-blocking layer or as matrix materialsin an emitting layer, preferably as matrix materials for fluorescentemitters). The compounds of formula (1) or (2) are very particularlysuitable as hole-transport materials or as matrix materials.

If the compounds of the formula (1) or (2) are employed ashole-transport material in a hole-transport layer, a hole-injectionlayer or an electron-blocking layer, the compound can be employed aspure material, i.e. in a proportion of 100%, in the hole-transportlayer, or it can be employed in combination with one or more furthercompounds. According to a preferred embodiment, the organic layercomprising the compound of the formula (1) or (2) then additionallycomprises one or more p-dopants. The p-dopants employed in accordancewith the present invention are preferably organic electron-acceptorcompounds which are able to oxidise one or more of the other compoundsof the mixture.

Particularly preferred embodiments of p-dopants are the compoundsdisclosed in WO 2011/073149, EP 1968131, EP 2276085, EP 2213662, EP1722602, EP 2045848, DE 102007031220, U.S. Pat. No. 8,044,390, U.S. Pat.No. 8,057,712, WO 2009/003455, WO 2010/094378, WO 2011/120709, US2010/0096600 and WO 2012/095143.

Particularly preferred as p-dopants are quinodimethane compounds,azaindenofluorendione, azaphenalene, azatriphenylene, 12, metal halides,preferably transition metal halides, metal oxides, preferably metaloxides containing at least one transition metal or a metal of the 3rdmain group and transition metal complexes, preferably complexes of Cu,Co, Ni, Pd and Pt with ligands containing at least one oxygen atom asbinding site. Also preferred are transition metal oxides as dopants,preferably oxides of rhenium, molybdenum and tungsten, particularlypreferably Re₂O₇, MoO₃, WO₃ and ReO₃.

The p-dopants are preferably distributed substantially uniformly in thep-doped layers. This can be achieved for example by co-evaporation ofthe p-dopant and of the hole-transport material matrix.

Particularly preferred p-dopants are selected from the compounds (D-1)to (D-13):

In an embodiment of the invention, the compounds of the formula (1) or(2) or the preferred embodiments are used in a hole-transport or-injection layer in combination with a layer which comprises ahexaazatriphenylene derivative, in particularhexacyanohexaazatriphenylene (for example in accordance with EP1175470). Thus, for example, preference is given to a combination whichlooks as follows: anode—hexaazatriphenylene derivative—hole-transportlayer, where the hole-transport layer comprises one or more compounds ofthe formula (1) or (2) or the preferred embodiments. It is likewisepossible in this structure to use a plurality of successivehole-transport layers, where at least one hole-transport layer comprisesat least one compound of the formula (1) or (2) or the preferredembodiments. A further preferred combination looks as follows:anode—hole-transport layer—hexaazatriphenylene derivative—hole-transportlayer, where at least one of the two hole-transport layers comprises oneor more compounds of the formula (1) or (2) or the preferredembodiments. It is likewise possible in this structure to use aplurality of successive hole-transport layers instead of onehole-transport layer, where at least one hole-transport layer comprisesat least one compound of the formula (1) or (2) or the preferredembodiments.

If the compounds of the formula (1) or (2) are employed as matrixmaterial in combination with a phosphorescent emitter in an emittinglayer, the phosphorescent emitter is preferably selected from theclasses and embodiments of phosphorescent emitters indicated below.Furthermore, one or more further matrix materials are preferably presentin the emitting layer in this case.

So-called mixed-matrix systems of this type preferably comprise two orthree different matrix materials, particularly preferably two differentmatrix materials. It is preferred here for one of the two materials tobe a material having hole-transporting properties and for the othermaterial to be a material having electron-transporting properties. Thecompounds of the formula (1) or (2) are preferably the material havinghole-transporting properties.

However, the desired electron-transporting and hole-transportingproperties of the mixed-matrix components may also be combined mainly orcompletely in a single mixed-matrix component, where the furthermixed-matrix component or components satisfy other functions. The twodifferent matrix materials may be present here in a ratio of 1:50 to1:1, preferably 1:20 to 1:1, particularly preferably 1:10 to 1:1 andvery particularly preferably 1:4 to 1:1. Mixed-matrix systems arepreferably employed in phosphorescent organic electroluminescentdevices. Further details on mixed-matrix systems are contained, interalia, in the application WO 2010/108579.

Particularly suitable matrix materials which can be used as matrixcomponents of a mixed-matrix system in combination with the compoundsaccording to the invention are selected from the preferred matrixmaterials for phosphorescent emitters indicated below or the preferredmatrix materials for fluorescent emitters, depending on what type ofemitter compound is employed in the mixed-matrix system.

Generally preferred classes of material for use as correspondingfunctional materials in the organic electroluminescent devices accordingto the invention are indicated below.

Suitable phosphorescent emitters are, in particular, compounds whichemit light, preferably in the visible region, on suitable excitation andin addition contain at least one atom having an atomic number greaterthan 20, preferably greater than 38 and less than 84, particularlypreferably greater than 56 and less than 80. The phosphorescent emittersused are preferably compounds which contain copper, molybdenum,tungsten, rhenium, ruthe-nium, osmium, rhodium, iridium, palladium,platinum, silver, gold or euro-pium, in particular compounds whichcontain iridium, platinum or copper.

For the purposes of the present invention, all luminescent iridium,platinum or copper complexes are regarded as phosphorescent compounds.

Examples of the phosphorescent emitters described above are revealed bythe applications WO 2000/70655, WO 2001/41512, WO 2002/02714, WO2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 2005/033244, WO2005/019373 and US 2005/0258742. In general, all phosphorescentcomplexes as used in accordance with the prior art for phosphorescentOLEDs and as are known to the person skilled in the art in the area oforganic electroluminescent devices are suitable for use in the devicesaccording to the invention. The person skilled in the art will also beable to employ further phosphorescent complexes without inventive stepin combination with the compounds according to the invention in OLEDs.

Preferred fluorescent emitters, besides the compounds according to theinvention, are selected from the class of the arylamines. An arylamineor aromatic amine in the sense of this invention is taken to mean acompound which contains three substituted or unsubstituted aromatic orheteroaromatic ring systems bonded directly to the nitrogen. At leastone of these aromatic or heteroaromatic ring systems is preferably acondensed ring system, particularly preferably having at least 14aromatic ring atoms. Preferred examples thereof are aromaticanthracenamines, aromatic anthracenediamines, aromatic pyrenamines,aromatic pyrenediamines, aromatic chrysenamines or aromaticchrysenediamines. An aromatic anthracenamine is taken to mean a compoundin which one diarylamino group is bonded directly to an anthracenegroup, preferably in the 9-position. An aromatic anthracenediamine istaken to mean a compound in which two diarylamino groups are bondeddirectly to an anthracene group, preferably in the 9,10-position.Aromatic pyrenamines, pyrenediamines, chrysenamines and chrysenediaminesare defined analogously thereto, where the diarylamino groups arepreferably bonded to the pyrene in the 1-position or in the1,6-position.

Preferred matrix materials for use with fluorescent emitters compoundsare indicated above.

Preferred matrix materials for phosphorescent emitters are aromaticketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones,for example in accordance with WO 2004/013080, WO 2004/093207, WO2006/005627 or WO 2010/006680, triarylamines, carbazole derivatives, forexample CBP (N,N-biscarbazolylbiphenyl) or the carbazole derivativesdisclosed in WO 2005/039246, US 2005/0069729, JP 2004/288381, EP 1205527or WO 2008/086851, indolocarbazole derivatives, for example inaccordance with WO 2007/063754 or WO 2008/056746, indenocarbazolederivatives, for example in accordance with WO 2010/136109, WO2011/000455 or WO 2013/041176, azacarbazole derivatives, for example inaccordance with EP 1617710, EP 1617711, EP 1731584, JP 2005/347160,bipolar matrix materials, for example in accordance with WO 2007/137725,silanes, for example in accordance with WO 2005/111172, azaboroles orboronic esters, for example in accordance with WO 2006/117052, triazinederivatives, for example in accordance with WO 2010/015306, WO2007/063754 or WO 2008/056746, zinc complexes, for example in accordancewith EP 652273 or WO 2009/062578, diazasilole or tetraazasilolederivatives, for example in accordance with WO 2010/054729,diazaphosphole derivatives, for example in accordance with WO2010/054730, bridged carbazole derivatives, for example in accordancewith US 2009/0136779, WO 2010/050778, WO 2011/042107, WO 2011/088877 orWO 2012/143080, triphenylene derivatives, for example in accordance withWO 2012/048781, or lactams, for example in accordance with WO2011/116865 or WO 2011/137951.

Besides the compounds according to the invention, suitablecharge-transport materials, as can be used in the hole-injection orhole-transport layer or electron-blocking layer or in theelectron-transport layer of the electronic device according to theinvention, are, for example, the compounds disclosed in Y. Shirota etal., Chem. Rev. 2007, 107(4), 953-1010, or other materials as areemployed in these layers in accordance with the prior art.

Materials which can be used for the electron-transport layer are allmaterials as are used in accordance with the prior art aselectron-transport materials in the electron-transport layer.Particularly suitable are aluminium complexes, for example Alq₃,zirconium complexes, for example Zrq₄, lithium complexes, for exampleLiq, benzimidazole derivatives, triazine derivatives, pyrimidinederivatives, pyridine derivatives, pyrazine derivatives, quinoxalinederivatives, quinoline derivatives, oxadiazole derivatives, aromaticketones, lactams, boranes, diazaphosphole derivatives and phosphineoxide derivatives. Furthermore suitable materials are derivatives of theabove-mentioned compounds, as disclosed in JP 2000/053957, WO2003/060956, WO 2004/028217, WO 2004/080975 and WO 2010/072300.

Preferred hole-transport materials which can be used in ahole-transport, hole-injection or electron-blocking layer in theelectroluminescent device according to the invention areindenofluorenamine derivatives (for example in accordance with WO06/122630 or WO 06/100896), the amine derivatives disclosed in EP1661888, hexaazatriphenylene derivatives (for exam-pie in accordancewith WO 01/049806), amine derivatives containing condensed aromaticrings (for example in accordance with U.S. Pat. No. 5,061,569), theamine derivatives disclosed in WO 95/09147,monobenzoindenofluoren-amines (for example in accordance with WO08/006449), dibenzoindenofluorenamines (for example in accordance withWO 07/140847), spiro-bifluorenamines (for example in accordance with WO2012/034627 or WO 2013/120577), fluorenamines (for example in accordancewith the as yet unpublished applications EP 12005369.9, EP 12005370.7and EP 12005371.5), spirodibenzopyranamines (for example in accordancewith WO 2013/083216) and dihydroacridine derivatives (for example inaccordance with WO 2012/150001). The compounds according to theinvention can also be used as hole-transport materials.

The cathode of the organic electroluminescent device preferablycomprises metals having a low work function, metal alloys ormultilayered structures comprising various metals, such as, for example,alkaline-earth metals, alkali metals, main-group metals or lanthanoids(for example Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable arealloys comprising an alkali metal or alkaline-earth metal and silver,for example an alloy comprising magnesium and silver. In the case ofmultilayered structures, further metals which have a relatively highwork function, such as, for example, Ag or Al, can also be used inaddition to the said metals, in which case combinations of the metals,such as, for example, Ca/Ag, Mg/Ag or Ag/Ag, are generally used. It mayalso be preferred to introduce a thin interlayer of a material having ahigh dielectric constant between a metallic cathode and the organicsemiconductor. Suitable for this purpose are, for example, alkali metalfluorides or alkaline-earth metal fluorides, but also the correspondingoxides or carbonates (for example LiF, Li₂O, BaF₂, MgO, NaF, CsF,Cs₂CO₃, etc.). Furthermore, lithium quinolinate (LiQ) can be used forthis purpose. The layer thickness of this layer is preferably between0.5 and 5 nm.

The anode preferably comprises materials having a high work function.The anode preferably has a work function of greater than 4.5 eV vs.vacuum. Suitable for this purpose are on the one hand metals having ahigh redox potential, such as, for example, Ag, Pt or Au. On the otherhand, metal/metal oxide electrodes (for example Al/Ni/NiO_(x),Al/PtO_(x)) may also be preferred. For some applications, at least oneof the electrodes must be transparent or partially transparent in orderto facilitate either irradiation of the organic material (organic solarcells) or the coupling-out of light (OLEDs, O-lasers). Preferred anodematerials here are conductive mixed metal oxides. Particular preferenceis given to indium tin oxide (ITO) or indium zinc oxide (IZO).Preference is furthermore given to conductive, doped organic materials,in particular conductive doped polymers.

The device is appropriately (depending on the application) structured,pro-vided with contacts and finally sealed, since the lifetime of thedevices according to the invention is shortened in the presence of waterand/or air.

In a preferred embodiment, the organic electroluminescent deviceaccording to the invention is characterised in that one or more layersare coated by means of a sublimation process, in which the materials areapplied by vapour deposition in vacuum sublimation units at an initialpressure of less than 10⁻⁵ mbar, preferably less than 10⁻⁶ mbar.However, it is also possible here for the initial pressure to be evenlower, for example less than 10⁻⁷ mbar.

Preference is likewise given to an organic electroluminescent device,characterised in that one or more layers are coated by means of the OVPD(organic vapour phase deposition) process or with the aid of carrier-gassublimation, in which the materials are applied at a pressure of between10⁻⁵ mbar and 1 bar. A special case of this process is the OVJP (organicvapour jet printing) process, in which the materials are applieddirectly through a nozzle and are thus structured (for example M. S.Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

Preference is furthermore given to an organic electroluminescent device,characterised in that one or more layers are produced from solution,such as, for example, by spin coating, or by means of any desiredprinting process, such as, for example, screen printing, flexographicprinting, nozzle printing or offset printing, but particularlypreferably LITI (light induced thermal imaging, thermal transferprinting) or ink-jet printing. Soluble compounds of the formula (1) or(2) are necessary for this purpose. High solu-bility can be achievedthrough suitable substitution of the compounds.

For the production of an organic electroluminescent device according tothe invention, it is furthermore preferred to apply one or more layersfrom solution and one or more layers by a sublimation process.

In accordance with the invention, the electronic devices comprising oneor more compounds according to the invention can be employed indisplays, as light sources in lighting applications and as light sourcesin medical and/or cosmetic applications (for example light therapy).

WORKING EXAMPLES A) Synthesis Examples

A-1) Compound A

The syntheses were performed according to the following general scheme:

Compound

Yield % Int-a1

79 Int-a2

83 Int-a3

70 Int-a4

87 Int-a5

75

Compound Int-a1

Phenoxazine (23 g, 0.12 mol), p-Bromphenylbenzene (31.22 g, 0.13 mol)and sodium tert-butoxide (35.83 g, 0.37 mol) are suspended in 800 ml oftoluene. The solution is degassed and saturated with argon. Thereafter,palladium (II) acetate (1.37 g, 1.88 mmol) and tri-tert-butylphosphine(solution 1 mol/L toluene, 0.01 mol) are added. The reaction mixture isheated overnight under reflux. The suspension is cooled and then treatedwith water. The collected organic phases are concentrated under vacuumand the remaining solid is purified by hot extraction. The yield is 32.4g (0.1 mol, 79% of the theory d. Theory) as a white solid.

The compounds Int-a2 to Int-a5 are prepared analogously to Int-a1.

Compounds Int-F-H (Compound Int-a6) and

Compound Int-F-Ph (Compound Int-a7)

Step 1:

Preparation of Int-F-H

10 g (54.6 mmol) Phenoxazine, 14.2 g (82 mmol)1,3-dichloro-2-fluoro-benzene and 25 g (0.11 mol) potassium phosphatewere dissolved in 250 mL DMF and stirred 16 hours at reflux. Aftercooling down to room temperature 300 ml toluene and 500 ml water wasadded and the phases were separated. The organic phase was washed withwater (3×300 ml) and the aqueous phase was extracted two times withtoluene. The combined organic phases were reduced to dryness andpurified by recrystallization from toluene/heptane.

Yield: 16 g (0.05 mol; 90%)

Preparation of Int-F-Ph

This compound can be prepared analogously to Int-F-H (yield 89%).

Step 2:

Int-F-H:

14 g (43 mmol) 10-(2,6-Dichloro-phenyl)-10H-phenoxazine, 13.7 g (107mmol) phenyl boronic acid, 26 g (171 mmol) caesium fluoride and 1.6 g(2.1 mmol) trans-dichlorobis(tricyclohexyl-phosphine)palladium (II) wererefluxed in 600 ml dioxane for 16 hours. After cooling down to roomtemperature toluene (300 ml) and water (400 ml) was added. The organicphase was washed with water (3×300 ml) and the aqueous phase wasextracted two times with toluene. The combined organic phases werereduced to dryness and purified by recrystallization fromtoluene/heptane.

Yield: 14.6 g (35 mmol; 82%)

For Int-F-Ph:

Compound can be prepared analogously to Int-F-H (yield 78%)

Compound

Yield % Int-b1

98 Int-b2

95 Int-b3

89 Int-b4

93 Int-b5

85 Int-b6

89 Int-b7

86

Compound Int-b1

The compound Int-a1 (32 g, 0.1 mol) is dissolved in 800 ml of glacialacetic acid and 800 ml of chloroform. Subsequently, N-Bromsucchinimid(34.8 g, 0.2 mol) is added slowly in the dark. After 4 hours, thereaction is quenched with water and the organic phase washed severaltimes with water. The resulting solid is extracted twice from hotethanol. The yield is 43.8 g (0.1 mol, 98% of the theory) as a whitesolid.

The compounds Int-b2 to Int-b7 are prepared analogously to Int-b1.

Compound

Yield % A1

59 A2

52 A3

46 A6

54 A7

57

Compound A1

The compound Int-b1 (20 g, 0.04 mol),2-(9,9-dimethylfluorene)-4,4,5,5-tetramethyldioxaborolane (27.27 g,0.085 mol) and tripotassium phosphate monohydrate (37.35 g, 0.16 mol)are suspended in 200 ml water, 200 ml of toluene and 200 ml of1,4-dioxane. The solution is degassed and saturated with argon.Subsequently, palladium (II) acetate (0.36 g, 1.6 mmol) andtri-ortho-tolylphosphine (1.48 g, 4.87 mmol) are added and the reactionboiled overnight under reflux. The suspension is cooled down and thentreated with water. The collected organic phases are concentrated undervacuum and the remaining solid is purified by hot extraction (toluene)and recrystallization (toluene and then EtOAc) purified. The yield is17.0 g (23.6 mmol, 59% of the theory) as a yellow solid.

The compounds A2 to A7 are prepared analogously to A1.

A-2) Compounds B

The syntheses were performed according to the following general scheme:

Int-c

Yield % Int-c1

66 Int-c2

75 Int-c3

82 Int-c4

62

Compound Int-c1

The compound Int-b1 (21.45 g, 0.05M), Bispinacolatodiborane (31.35 g,0.12 mol) and potassium acetate (30.3 g, 0.31 mol) are suspended in 500ml of 1,4-dioxane. The reaction mixture is degassed and saturated withargon. Then [1,1′-bis-diphenylphosphino-ferrocene] palladium (11)dichloride (3.35 g, 4.1 mmol) is added and the reaction is stirredovernight under reflux. The suspension is cooled down and filtereddirectly over alumina. The resulting solid is stirred in hot ethanol.The yield is 17.25 g (0.033 mol, 66% of the theory) as a white solid.

The compounds Int-c2 to Int-c4 are prepared analogously to Int-c1.

Int-d

Yield % Int-d1

65 Int-d3

63

Compound Int-d1

The compound Int-c1 (17 g, 0.033 mol), 1-bromo-phenyl-ethyl ester (18.74g, 0.067 mol) and tripotassium phosphate monohydrate (30.39 g, 0.132mol) are suspended in 50 ml water, 50 ml of toluene and 50 ml1,4-dioxane. The solution is degassed and saturated with argon.Subsequently, palladium (II) acetate (0.29 g, 1.32 mmol) andtri-ortho-tolylphosphine (1.21 g, 3.96 mmol) are added and the reactionis boiled overnight under reflux. The suspension is cooled down and thentreated with water. The collected organic phases are concentrated undervacuum and the remaining solid is purified by hot extraction (toluene)and recrystallization (toluene/heptane). The yield is 14.1 g (00.21 mol,65% of the theory) as a yellow solid.

The compound Int-d3 is prepared analogously to Int-d1.

Int-e

Yield % Int-e1

95 Int-e3

93

Compound Int-e1

Cerium (Ill) chloride (11.3 g, 0.046 mol) is initially added to dry THF,then the compound Int-d1 (14 g, 0.021 mol) is dissolved in dry THF andthe solution is added dropwise to the reaction mixture, which issubsequently stirred for one hour. Afterwards, a solution of MeMgCl (3Min THF, 0.13 mol) is added to the reaction mixture dropwise. After 2hours, the reaction is heated overnight to room temperature. Under icecooling, the reaction is quenched with water. After phase separation,the organic phase is dried and the solvent evaporated. The organic phaseis then purified via recrystallisation from heptane/toluene. The yieldis 12.5 g (0.02 mol, 95% of the theory) as a yellow solid.

The compound Int-e3 is prepared analogously to Int-e1.

B

Yield % B1

82 B3

87

Compound B1

Polyphosphoric acid (13.1 g, 0.13 mol) and methanesulfonic acid (12.5 g,0.13 mol) are placed in a flask. Then, a solution comprising thecompound Int-e1 (12 g, 0.019 mol) suspended in DCM is slowly added intothe reaction mixture, which is cooled down with an ice bath. Thereaction mixture is further stirred during 2 hours and is subsequentlytreated with ethanol. After adding water, a phase separation occurs. Theorganic phase is washed with water, then dried and then the solvent isevaporated. The remaining residue is recrystallized several times fromtoluene/heptane.

The yield is 8.65 g (0.15 mol, 77% of the theory) as a yellow solid.

The compound B3 is prepared analogously to BI.

B) Device Examples

Fabrication of OLED devices

The manufacturing of the OLED devices is performed accordingly to WO04/05891 with adapted film thicknesses and layer sequences. Thefollowing examples V1 to E5 (see Table 1) show data of various OLEDdevices.

Substrate Pre-Treatment of Examples V1-E5:

Glass plates with structured ITO (50 nm, indium tin oxide) are coatedwith 20 nm PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)poly(styrene-sulfonate, CLEVIOS™ P VP AI 4083 from Heraeus PreciousMetals GmbH Germany, spin-coated from a water-based solution) to formthe sub-strates on which the OLED devices are fabricated.

The OLED devices have in principle the following layer structure:

-   -   Substrate,    -   ITO (50 nm),    -   Buffer (20 nm),    -   Hole injection layer (HTL1 95%, HIL 5%) (20 nm),    -   Hole transporting layer (HTL1) (see table 1),    -   Emissive layer (EML) (20 nm),    -   Electron transporting layer (ETL) (30 nm),    -   Electron injection layer (EIL) (3 nm),    -   Cathode.

The cathode is formed by an aluminium layer with a thickness of 100 nm.The detailed stack sequence is shown in Table 1. The materials used forthe OLED fabrication are presented in Table 3.

All materials are applied by thermal vapour deposition in a vacuumchamber. The emission layer here always consists of at least one matrixmaterial (host material=H) and an emitting dopant (emitter=D), which ismixed with the matrix material or matrix materials in a certainproportion by volume by co-evaporation. An expression such as H1:D1(97%:3%) here means that material H1 is present in the layer in aproportion by volume of 97%, whereas D1 is present in the layer in aproportion of 3%. Analogously, the electron-transport layer may alsoconsist of a mixture of two or more materials.

The OLED devices are characterised by standard methods. For thispurpose, the electroluminescence spectra, the current efficiency(measured in cd/A) and the external quantum efficiency (EQE, measured in% at 1000 cd/m²) are determined from current/voltage/luminancecharacteristic lines (IUL characteristic lines) assuming a Lambertianemission profile. The electroluminescence (EL) spectra are recorded at aluminous density of 1000 cd/m² and the CIE 1931 x an y coordinates arethen calculated from the EL spectrum. EQE @ 1000 cd/m² is defined as theexternal quantum efficiency at luminous density of 1000 cd/m². For allexperiments, the lifetime LT95 is determined. The lifetime LT95 @1000cd/m² is defined as the time after which the initial luminous density of1000 cd/m² has dropped by 5%. The device data of various OLED devices issummarized in Table 2.

The example V1 represents the comparative example according to thestate-of-the-art. The examples E1-E5 show data of inventive OLEDdevices.

In the following section several examples are described in more detailto show the advantages of the inventive OLED devices.

Use of Inventive Compounds as Emitting Material in Fluorescent OLEDs

The inventive compounds are especially suitable as an emitter (dopant)when blended into a fluorescent blue matrix to form the emissive layerof a fluorescent blue OLED device. The representative examples are D1,D2, D3, D4 and D5. Comparative compound for the state-of-the-art isrepresented by VD (structures see table 3).

The use of the inventive compound as an emitter (dopant) in afluorescent blue OLED device results in significantly improved devicedata (E1, E2, E3, E4 and E5) compared to state-of-the-art example (V1),especially in term of external quantum efficiency and device lifetime.This demonstrates the applicability of the inventive compound asemitting material in fluorescent blue OLED devices. The material can bealso used also as hole transporting material.

TABLE 1 Stack sequence of OLEDs Example HTL (20 nm) EML (Dicke/20 nm) V1HTL2 BH1 (97%):VD (3%) E1 HTL2 BH1 (97%):D1 (3%) E2 HTL2 BH1 (97%):D2(3%) E3 HTL2 BH1 (97%):D3 (3%) E4 HTL2 BH1 (97%):D4 (3%) E5 HTL2 BH1(97%):D5 (3%)

TABLE 2 Device data of OLEDs EQE [%] @ LT 95 [h] @ Example CIE x CIE y1000 cd/m² 1000 cd/m² V1 0.14 0.18 6.2 80 E1 0.15 0.17 6.8 150 E2 0.140.14 6.5 200 E3 0.14 0.15 6.7 100 E4 0.15 0.13 6.9 130 E5 0.15 0.13 6.8170

TABLE 3 Chemical structure of OLED materials

HTL1

HTL2

D1

D2

D3

D4

D5

The invention claimed is:
 1. A compound of formula (1) or formula (2):

wherein Ar is an aromatic ring system selected from one of the followingformulae (ArN-1) to (ArN-24) and (ArN-26),

where the groups (ArN-1) to (ArN-24) and (ArN-26), are optionallysubstituted by one or more radicals R²; Ar¹ is, on each occurrence,identically or differently, a group of formulae (Ar1′-1) through(Ar1′-4):

wherein the dashed bond denotes the linking to Ar^(S) or to aphenoxazine structure if A^(S) is absent; V is, on each occurrence,identically or differently, CR² or N or two adjacent groups V are agroup of formula (V-1) or (V-2);

wherein the dashed bonds denote the linking of these units; Ar² is, oneach occurrence, identically or differently, an aryl group having 10 to18 aromatic ring atoms, which is optionally substituted by one or moreradicals R²; A^(S) is, on each occurrence, identically or differently,an aromatic or heteroaromatic ring system having 5 to 40 aromatic ringatoms, optionally substituted by one or more radicals R²; E¹, E², and E³are, on each occurrence, identically or differently, selected from thegroup consisting of B(R¹), C(R¹)₂, Si(R¹)₂, C═O, C═NR¹, C═C(R¹)₂, O, S,S═O, SO₂, N(R¹), P(R¹), and P(═O)R¹; or E¹, E² and/or E³ is a group offormula (E-1):

wherein the dashed bonds denote the bonding to the 5-membered ringcomprising E¹, E², or E³; R, and R³ are, on each occurrence, identicallyor differently, H, D, F, Br, Cl, I, C(═O)R⁴, CN, Si(R⁴)₃, N(R⁴)₂,P(═O)(R⁴)₂, S(═O)R⁴, S(═O)₂R⁴, a straight-chain alkyl or alkoxy grouphaving 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy grouphaving 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 Catoms, optionally substituted by one or more radicals R⁴ and wherein oneor more CH₂ groups are optionally replaced by —R⁴C═CR⁴—, —C≡C—, Si(R⁴)₂,C═O, C═NR⁴, —C(═O)O—, —C(═O)NR⁴—, NR⁴, P(═O)(R⁴), —O—, —S—, SO, or SO₂,an aromatic or heteroaromatic ring system having 5 to 30 aromatic ringatoms, optionally substituted by one or more radicals R⁴, or an aryloxyor heteroaryloxy group having 5 to 30 aromatic ring atoms, which isoptionally substituted by one or more radicals R⁴, wherein two adjacentradicals R, and/or two adjacent radicals R³ are optionally linked to oneanother and optionally define an aliphatic or aromatic ring; R¹ isselected, identically or differently on each occurrence, from the groupconsisting of H, D, F, a straight-chain alkyl group having 1 to 10 Catoms or a branched or cyclic alkyl group having 3 to 10 C atoms,optionally substituted by one or more radicals R⁴; R² is selected,identically or differently on each occurrence, from the group consistingof H, D, F, a straight-chain alkyl group having 1 to 10 C atoms or abranched or cyclic alkyl group having 3 to 10 C atoms, optionallysubstituted by one or more radicals R⁴, a phenyl group, optionallysubstituted by one or more radicals R⁴; R⁴ is, on each occurrence,identically or differently, H, D, F, Br, Cl, I, C(═O)R⁵, CN, Si(R⁵)3,N(R⁵)₂, P(═O)(R⁵)₂, S(═O)R⁵, S(═O)₂R⁵, a straight-chain alkyl or alkoxygroup having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxygroup having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to20 C atoms, optionally substituted by one or more radicals R⁵ andwherein one or more CH₂ groups are optionally replaced by —R⁵C═CR⁵—,—C≡C—, Si(R⁵)2, C═O, C═NR⁵, —C(═O)O—, —C(═O)NR⁵—, NR⁵, P(═O)(R⁵), —O—,—S—, SO, or SO₂, an aromatic or heteroaromatic ring system having 5 to30 aromatic ring atoms, optionally substituted by one or more radicalsR⁵, or an aryloxy or heteroaryloxy group having 5 to 30 aromatic ringatoms, which is optionally substituted by one or more radicals R⁵, wheretwo adjacent radicals R⁴ are optionally linked to one another andoptionally define an aliphatic or aromatic ring; R⁵ is, on eachoccurrence, identically or differently, H or an aliphatic, aromatic,and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms,wherein H atoms are optionally replaced by F; and wherein two adjacentradicals R⁵ also optionally define a mono- or polycyclic aliphatic oraromatic ring system with one another; a, b, c, and d are, identicallyor differently, selected from 0 or 1; wherein a =0, b =0, c =0, or d =0denotes that the corresponding bridge is not present; wherein a+b=1 or2; and c+d=1 or 2; f is, identically or differently, on each occurrence0, 1, 2, or 3; g and h are, identically or differently, on eachoccurrence 0, 1, or 2; wherein g+a+b ≤3 and h+c+d≤3; m is, identicallyor differently, on each occurrence 0, 1, 2, 3, or 4; and i is,identically or differently, on each occurrence 0, 1, 2, or 3, whereini=0 denotes that the group Ar^(S) is absent and replaced by a singlebond.
 2. The compound of claim 1, wherein a+c=1 and b+d=0 or b+d=1 anda+c=0.
 3. The compound of claim 1, wherein Ar² is selected from thegroup consisting of naphthyl, anthracyl, phenanthryl, chrysenyl, andpyrenyl, wherein each of which is optionally substituted by one or moreradicals R².
 4. The compound of claim 1, wherein the compound isselected from group consisting of compounds of formulae (1-1-a),(2-1-a), and (2-2-a):

wherein Ar² is a group of formulae (Ar2-1) through (Ar2-3)

wherein the dashed bond denotes the linking to the phenoxazine structureand * indicates the linking position to the group E²; and wherein eachfree position on the naphtyl group in formulae (Ar2-1) through (Ar2-3)is optionally substituted by a radical R²; with the proviso that informula (1-1-a), V is C when the linking to the phenoxazine structure ora phenyl phenoxazine structure takes place via V.
 5. The compound ofclaim 1, wherein the compound is selected from group consisting ofcompounds of formulae (1-1-b) through (2-2-d):

wherein formulae (1-1-b) through (2-2-d) have two phenyl rings condensedon a central oxazine ring, and wherein each free position of the twophenyl rings condensed on the central oxazine ring in formulae (1-1-b)through (2-2-d) is optionally substituted by a radical R.
 6. Thecompound of claim 1, wherein E¹, E², and E³ are, on each occurrence,identically or differently, selected from the group consisting ofC(R¹)₂, Si(R¹)₂, O, N, S, and groups of formula (E-1).
 7. The compoundof claim 1, wherein R and R³ are selected, identically or differently oneach occurrence, from the group consisting of H, D, F, CN, astraight-chain alkyl group having 1 to 20 C atoms or a branched orcyclic alkyl group having 3 to 20 C atoms, optionally substituted by oneor more radicals R⁴ and wherein one or more CH₂ groups are optionallyreplaced by —R⁴C═CR⁴—, —C≡C—, C═O, —O—, —S—, an aromatic orheteroaromatic ring system having 5 to 30 aromatic ring atoms, which ineach case is optionally substituted by one or more radicals R⁴, andwherein two adjacent radicals R, and/or two adjacent radicals R³ areoptionally linked to one another and optionally define an aliphatic oraromatic ring.
 8. A process for preparing a compound of claim 1,comprising introducing aryl groups as substituents para to the N atom ofa phenoxazine derivative via one or more transition metal-catalysedcoupling reactions.
 9. An oligomer, polymer or dendrimer comprising oneor more compounds of claim 1, wherein the bond(s) to the polymer,oligomer, or dendrimer are optionally localised at any desiredposition(s) in formula (1) or in formula (2) substituted by R or R². 10.A formulation comprising at least one compound of claim 1 and at leastone solvent.
 11. A formulation comprising at least one polymer,oligomer, or dendrimer of claim 9 and at least one solvent.
 12. Anelectronic device comprising at least one compound of claim
 1. 13. Anelectronic device comprising at least one polymer, oligomer, ordendrimer according to claim
 9. 14. The electronic device of claim 12,wherein the electronic device is selected from the group consisting oforganic integrated circuits, organic field-effect transistors, organicthin-film transistors, organic light-emitting transistors, organic solarcells, organic optical detectors, organic photoreceptors, organicfield-quench devices, light-emitting electrochemical cells, organiclaser diodes, and organic electroluminescent devices.
 15. The electronicdevice of claim 13, wherein the electronic device is selected from thegroup consisting of organic integrated circuits, organic field-effecttransistors, organic thin-film transistors, organic light-emittingtransistors, organic solar cells, organic optical detectors, organicphotoreceptors, organic field-quench devices, light-emittingelectrochemical cells, organic laser diodes, and organicelectroluminescent devices.
 16. The electronic device of claim 12,wherein the electronic device is selected from the group consisting oforganic electroluminescent devices and wherein the compound is employedin one or more of the following functions: as a blue emitter in anemitting layer, as a hole-transport material in a hole-transport orhole-injection layer, as a matrix material in an emitting layer, as anelectron-blocking material; and as an exciton-blocking material.
 17. Theelectronic device of claim 13, wherein the electronic device is selectedfrom the group consisting of organic electroluminescent devices andwherein the polymer, oligomer or dendrimer is employed in one or more ofthe following functions: as a blue emitter in an emitting layer, as ahole-transport material in a hole-transport or hole-injection layer, asa matrix material in an emitting layer, as an electron-blockingmaterial; and as an exciton-blocking material.